1. Field of the Invention
The present invention relates to a three-unit zoom lens system of a small size, and an image pickup apparatus such as a compact digital camera in which the three-unit zoom lens system is used.
2. Description of the Related Art
In an image pickup apparatus such as a digital camera and a video camera, a high image quality, a high magnification, and a thinning of a lens frame have been sought. For example, a zoom lens system which includes a first lens unit having a negative refracting power, a second lens unit having a positive refracting power, and a third lens unit having a negative refracting power as described in Japanese Patent Application Laid-open Publication No. 2004-333572 has hitherto been known. This zoom lens system has a comparatively favorable optical performance, while securing a high magnification ratio of about 4.
Moreover, recently, an image pickup element which picks up a favorable image even when an angle of incidence of light rays incident on a portion around an image pickup area of an image pickup element is made large as described in Japanese Patent Application Laid-open Publication No. 2006-351972 has been known.